Refrigerating apparatus



Dec. 8, i931. H, Ev HULL REFRIGERATING APPARATUS Filed June 27. 1929 2 Sheets-Sheet Dec. 8, 1931. H, B. HULL REFRGERATING APPARATUS 2 Sheets-Sheet.

Filed June 27. 1929 Patented Dec. 8, 1931 rTED STATES PATENT OFFICEA HARRY B. HULL, OF DAYTON, OHIO, ASSIGNOR T FRIGIDAIRE CORPORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE REFRIGERATING APPARATUS Application led .Tune 27,

This invention relates to refrigerating apparatus andv particularly to an improved construction of refrigerating element.

One of the objects of the invention is to a provide an improved refrigerating element particularly adapted for small cabinets, which will occupy a small amount of space.

Another object of the invention is to provide an improved refrigerating element of 1o such small size with maximum ice freezing capacity.

A still further object is to provide an 1mproved refrigerating element of the dry expansion type which both freezes ice rapidly le and cools a cabinet effectively.V

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the invention is clearly shown.

In the drawings:

Fig. 1 is an elevation of a refrigerating cabinet showing a cooling unit constructe( andl arranged according to the present invention mounted therein.

Fig. 2 is a front elevation on an enlarged" scale of theimproved refrigerating element. Fig. 3 is a side elevation of the element. Fi 4 is a bottom plan view of the element. Fig. 5 is a diagrammatic representation of a refrigerating system including my improved refrigerating element therein.

Referring particularly to Fig. 1, 1() designates a refrigerator cabinet of any suitable construction which has a door 11l adapted to seal a refrigerating compartment 12 formed by the cabinetl top, back and side walls. The side walls and top wall meet at corners in one of which is placed a refrigerating element of the type herein disclosed. The refrigerating element is disposed in the corner as close to the top wall as construction and frosting conditions Will permit. The clement is spaced a short distance from the side wall and its construction permits v air circulation thereover. I have found that the cooling element may be placed very close to the top 'wall since the heat leakage in the downward direction thru the top Wall is relatively small. The refrigerating element in- 1929. serial No. 3731561.

cludes a freezing compartment to be 'more' fully described herein and means projecting from the walls of the freezing compartment for cooling the air in cabinet and setting up circulation. This means is a number of loops of pipe constituting a part of the refrigerating element and contactinff the side Walls and extending away from tie'top and bottom of the freezing compartment. The air may circulate freely be- 6c tween"^these loops, thru which refrigerant circulates and is cooled' by it.

Beneath the refrigerating element is placed a defrosting pan 21, slidably supported Lby one of the food storage shelves 22 o5 which is provided with tracks 23 for receiving an outwardly turned flange provided on the pan 21. These tracks 23 serve as a guide to insure the placing. of the pan 2l directly beneath the refrigerating element. When the refrigerating apparatus is operating the pan serves as a convenient storage for articles to be kept very cold, such as ice cubes, and when the refrigerating element is being defrosted the pan 21 serves to collect the water which drips from the element. Air chilled by the element sinks into the pan and overflows into the cabinet and' sets up the circulation of air which refrigerates the cab inet in the well-known manner.

Figs. 2, 3 and 4 show in detail one form of construction of the refrigeratin element. This preferably'includes a coil o tubing 25 which is flattened to provide maximum contact thereof with the air circulating there- 85 over. Within the coil 25 is placed a freezing compartment 30 adapted to receive two freezing containers 31. Side walls of the compartment 30 are soldered to the vertical inner surface of coil 25. It has been found that the majority of the heat conducted away from such freezing containers in apparatus of this sort when freezing ice cubes for example, is conducted thru the bottom of the freezing container and freezing compartment to the refrigerant in the refrigerating element, and that water can be frozen more quickly by securing the freezing compartment along the bottom to a refrigerant conduit than by attaching the conduit in any flat spiral coil 32 and thus eliminates the ne# cessity ,of constructing complicated and expensive refrigerating elements to obtain rapid freezing effects. Coil 32 comprises a length of tubing slightly smaller in diameter than the coil of tubing and is connected in series with the coil 25 by a connection 33 (see Fig. 4). The two coils thus form a single continuous conduit. The convolutions of the lcoil 25 are held in spaced relation by a number of braces 34, which are soldered to the convolutions as shown in Figs. 2 and 3. Brace 34 located at the bottom of the element has been omitted in Fig. 4 for the sake of more clearly showing the convolutions of spiral coil 32. Y

At the ends of the compartment beyond the coils are secured a pair of brackets 36 and 37 having feet 38 by which the refrig erating element is supported on the top wall of the cabinet. A cover or shield 40 is secured to the partition 41located at the front of the refrigerating element in any suitable manner. This cover 40 may be coated with vitreous enamel or may be made of polished non-corroding metal such as monel, in order to enhance the appearance of the cooling unit. The shield 40 is provided with openings registering with the openings of Acompartment 30 to permit the insertion of the ice trays 31. The front bracket 36 is provided with a strap 43 which spans the space between the ends thereof and is secured to the feet 38 formed thereon by rivets 44. Strap 43 is provided with slots 45 which receive screws 46 for attaching an expansion valve 50 which is provided for the purpose of controlling the supply of refrigerant to the refrigerating element. The particular construction Of the valve 50 forms no part of the present invention and may be for example as shown in my copending application S. N.

183,480, filed April 13, 1927. A thermostat bulb 51 (see Fig. 5) may be secured to the refrigerating element in any suitable location to control the refrigerant circulating device in response to the refrigerating demand.

Referring to the Fig. 5 in the drawings, the refrigerating circuit to which the invention is applied by Way of illustration, conlprises a refrigerant circulating means for example a compressor 6() driven by a motor 61 which is controlled by a thermostatically operated switch 62 actuated by pressure in bulb 51 which pressure is responsive to the temperature of the system. The compressor forces a refrigerating medium, for example sulphur dioxide, thru pipe 63 into condenser 64 Where the medium is cooled. The

condensed refrigerant medium collects in receiver 65 and is directed to the expansion valve 50 by pipe 66 from where it is permitted to enter the coils 32 and 25 of a refrigerating element where it produces its refrigerating effect in the well-known manner. Expanded refrigerant is withdrawn from the evaporating coil 25. by the compressor 60 thru a pipe 67.

lIt will be appreciated that a refrigerating element must be of a given cross section in v order to receive ice trays of a size which is regarded as essential in present-day practice. The necessary heat exchange surface for cooling small cabinets may then be made on such a refrigerating element Within a length considerably less than the depth of the freezing compartment. Convolutions of the coil provided for cooling the cabinet may therefore be spaced apart to permit free air circulation thereover. The particular form of cooling unit shown provides ample space between the freezing compartment and the Ytop of unit for receiving the expansion valve 50. Thus the depth of the refrlgerating element is reduced and therefore occupies a minimum amount of space leaving max-4 imum space in the cabinet for the convenien storage of food.-

In dry expansion refrigerating elements of this type the temperature of the refrigerating conduit or the amount of refrigeration tively cool the-food storage compartment of cabinet will also occur in coil 25.

The Cooling unit is designed so that coil will furnish sufficient refrigeration to rapidly freeze water in the freezing compartment, and the coil y25 whichsllrrounds the freezing compartment is intended primarily for cooling the circulating air. The device is preferabl operated so that the entire coil 32 isfloo ed with refrigerant. The coil 25 may or may not be entirely flooded. That is, when the apparatus is first assembled the expansion Valye is vso adjusted that frost appears on the whole of the first coil 32 and the second coil 25 is frosted from its point of connection to the rst coil 32 to some point intermediate its ends. T he frost line or point where the frostinir on thecoil stops indicates how much of the conduit isl flooded. By properly proportioning the parts, the system may be operated so that the coil 25 does not remain coated with frost during the entire operation. lt will be understood that the apparatus is periodically operated. During the operating periods frost may form on the entire evaporator, but due to the large surface of coil 25 exposed to the circulating air this coil can ordinarily be defrosted during the periods when the device is not circulating refrigerant. This leaves the coil 25 bare for the subsequent operating period and -enables the transfer of the maximum amount of heat. rlhe inner coil 32 can be completely coated with frost and remain frosted during the non-operating periods and thus rotect the ice Within the compartment 30 rom being melted bythe circulating air.

Fromifthe foregoing it is apparent that l' have provided a small compact cooling unit which can be cheaply manufactured and which will rapidly freeze substances located in trays and adapted to be placed in the unit While at the same time ec'iently cooling a small size cabinet such as is used in apartments and small homes.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of t-he claims which follow.

What is claimed is as follows:

l. Refrigerating apparatus comprising in combination, a single continuous conduit forming a refrigerating element, a compartment for a freezing container, a flat spiral coil formed by the continuous conduit and secured to the bottom wall of said compartment, and a coil formed by the continuous conduit enclosing said compartment and said spiral coil, U shaped brackets secured to the compartment and having feet formed thereon adapted to receive means for supporting the refrigerating element, a mounting for an expansion valve extending between and. secured to the feetformed on one of said brackets, and an expansion valve supported by said mounting and connected with the first named coil.

2. Refrigerating apparatus comprisingin combination, a single continuous conduit forming a refrigerating element, said element comprising a flat spiral coil for intimate thermal contact with a horizontal ice tray, an open horizontally disposed air cooling coil formed by said continuous conduit and surrounding said spiral coil.

3. Refrigerat-ing apparatus comprising in combination, a single continuous conduit forming a refrigeratlng element, an elongated horizontally disposed su port for a freezing container, a at spiral reezing coil "formed by the continuous conduit and secured in intimate thermal contact to the bottom wall of forming a refrigerating element, an elongated horizontally disposed sleeve for a freezing container, a flat spiral freezing coil formed by the continuous conduit and secured in intimate thermal contact to the bottom Wall of said sleeve, an open horizontally disposed air cooling coil formed by the continuous conduit and enclosing said sleeve and spiral coil, convolutions of said air cooling coil each having a portion secured in intimate thermal contact with a side Wall of said sleeve.

6. Refrigerating apparatus comprising in combination, a single continuous conduit forming a refrigerating element, an elongated horizontally disposed sleeve for a freezing container, a dat spiral freezing coil formed by the continuous conduit and secured in intimate thermal contact to the bottom Wall of said sleeve, an open horizontally disposed air cooling coil formed by the continuous conduit and enclosing said sleeve and spiral coil, convolutions of said spiral coil being round in cross-section, and convolutions of said air cooling coil being substantially dat in cross-section.

7. A refrigerating element comprising in combination, an elongated horizontally disposed sleeve for a freezing container, a flat spiral coil secured in intimate thermal contact to theA bottom wall of said sleeve, said coil having its inlet end connected to an expansion valve and its outlet end connected to a second coil, said second coil being open and horizontally disposed and enclosingsaid sleeve and spiral coil, said second coil having itsl outlet end connected With a refrigerant circulating device.

In testimony whereof I hereto affix my signature.

HARRY B. HULL. 

